xref: /openbmc/linux/arch/arm64/include/asm/lse.h (revision d9fd5a71)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_LSE_H
3 #define __ASM_LSE_H
4 
5 #include <asm/atomic_ll_sc.h>
6 
7 #ifdef CONFIG_ARM64_LSE_ATOMICS
8 
9 #define __LSE_PREAMBLE	".arch_extension lse\n"
10 
11 #include <linux/compiler_types.h>
12 #include <linux/export.h>
13 #include <linux/jump_label.h>
14 #include <linux/stringify.h>
15 #include <asm/alternative.h>
16 #include <asm/atomic_lse.h>
17 #include <asm/cpucaps.h>
18 
19 extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
20 extern struct static_key_false arm64_const_caps_ready;
21 
22 static inline bool system_uses_lse_atomics(void)
23 {
24 	return (static_branch_likely(&arm64_const_caps_ready)) &&
25 		static_branch_likely(&cpu_hwcap_keys[ARM64_HAS_LSE_ATOMICS]);
26 }
27 
28 #define __lse_ll_sc_body(op, ...)					\
29 ({									\
30 	system_uses_lse_atomics() ?					\
31 		__lse_##op(__VA_ARGS__) :				\
32 		__ll_sc_##op(__VA_ARGS__);				\
33 })
34 
35 /* In-line patching at runtime */
36 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)				\
37 	ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
38 
39 #else	/* CONFIG_ARM64_LSE_ATOMICS */
40 
41 static inline bool system_uses_lse_atomics(void) { return false; }
42 
43 #define __lse_ll_sc_body(op, ...)		__ll_sc_##op(__VA_ARGS__)
44 
45 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)	llsc
46 
47 #endif	/* CONFIG_ARM64_LSE_ATOMICS */
48 #endif	/* __ASM_LSE_H */
49